TOEFL Listening: ETS-TOEFL听力机经 - EDZ94XYEF93R7J53P$

What questions were the subjects asked to answer in the research study that the professor describes? A. How confident they were about their judgments. B. Whether they were distracted by the frequently changing screens. C. Which of the two screens contained a brighter patch. D. How many patches were shown on the two screens.